This is an interesting question and I have come across this alot of times in my life- from friends and family. Hinduism does not prohibit any of it's followers from keeping a positive attitude towards other religions. It is believed that different religions are like different spokes of a wheel, all pointing and leading to the same central point of the wheel. Similarly all religions (though having their own ideologies and beliefs) point to the same supreme power i.e. "God". Teachings of Ramakrishna believe in the popular saying "Jato math, Tato path" which means that as many number of people, as many number of paths. Ultimately, each and every human being follows a single path which ultimately leads to a common power called god.